Orthorectification of prisma images

Orthorectification is one of the most important satellite imagery pre-processing applications, as it allows to use data, for example, in geographic information systems, making the most of high or medium resolution. Since May 2020, PRISMA (PRecursore IperSpettrale della Missione Applicativa) mission, a project of the Italian Space Agency, has become fully accessible to the community. PRISMA satellite integrates a hyperspectral sensor and a medium-resolution panchromatic sensor. The products are currently available with a declared geolocation accuracy of 200 m, which ASI plans to increase to half pixel in the near future by introducing geometric treatment of the images with Ground Control Points (GCPs). However, the orthorectification of PRISMA images is not a proven and validated procedure, due to the uncertainty of satellite orbital and internal orientation data provided in the metadata file and to the lack of contributions on the subject in literature. In the present work, our contribution on possible strategies for the geometric treatment of PRISMA images is shown. The results obtained by applying the Rational Polynomial Coefficients (RPC) provided with some panchromatic images show coarse rototranslations. For this reason, a procedure was developed to restore conformity between RPCs and the panchromatic image. The best results in terms of accuracy were obtained with the rational polynomials using RPF approach, achieving residuals calculated on the Check Points (CP) in the order of one pixel, better than those supposed by ASI using GCPs. Probably even better results could be obtained with more rigorous information on RPCs or orbital and orientation parameters

Studio delle possibilità di utilizzo della costellazione Glonass nel suo stato

GLONASS (Global Navigation Satellite System) is a global position satellite system realized by ex- Urss at the same time with the United State’s one. The first launch of satellites went back to 12th October 1982, they completed constellation with 24 satellites in 1997. In the years Russia didn’t have economic force to maintain active the entire constellation. But in 2002 GLONASS relaunching started, that provides 18 satellites before 2007, and it will reach 24 satellites before 2010. The program provides the launch of three or two rockets a year, each one will bring to space two or three satellite. At present (15th September 2006) there are 15 operative GLONASS satellites. The aim of this work is to show the potentiality of the jointed use of GPS and GLONASS satellites by performing an adequate subdivision of the observations collected during a survey in the area of Rome using TOPCON receivers able to acquire data coming from both constellations

First considerations on post processing kinematic GNSS data during a geophysical oceanographic cruise

Differential GNSS positioning on vessels is of considerable interest in various fields of application as navigation aids, precision positioning for geophysical surveys or sampling purposes especially when high resolution bathymetric surveys are conducted. However ship positioning must be considered a kinematic survey with all the associated problems. The possibility of using high-precision differential GNSS receivers in navigation is of increasing interest, also due to the very recent availability of low-cost differential receivers that may soon replace classic navigation ones based on the less accurate point positioning technique. The availability of greater plano-altimetric accuracy, however, requires an increasingly better understanding of planimetric and altimetric reference systems. In particular, the results allow preliminary considerations on the congruence between terrestrial reference systems (which the GNSS survey can easily refer to) and marine reference systems (connected to National Tidegauge Network). In spite of the fluctuations due to the physiological continuous variation of the ship's attitude, GNSS plot faithfully followed the trend of the tidal variations and highlighted the shifts between GNSS plot and the tide gauges due to the different materialization of the relative reference systems

Common faith or parting ways? A time varying parameters factor analysis of euro-area inflation

We analyze the interaction among the common and country specific components for the inflation rates in twelve euro area countries through a factor model with time varying parameters. The variation of the model parameters is driven by the score of the predictive likelihood, so that, conditionally on past data, the model is Gaussian and the likelihood function can be evaluated using the Kalman filter. The empirical analysis uncovers significant variation over time in the model parameters. We find that, over an extended time period, inflation persistence has fallen over time and the importance of common shocks has increased relatively to the idiosyncratic disturbances. According to the model, the fall in inflation observed since the sovereign debt crisis, is broadly a common phenomenon, since no significant cross country inflation differentials have emerged. Stressed countries, however, have been hit by unusually large shocks

APPLICABIILITA’ DELL’APPROCCIO MULTICOSTELLATION CON L’AUSILIO DI SOFTWARE COMMERCIALI NELLA RETE UNIPA

Lo sviluppo dei sistemi di radio navigazione satellitare richiede lo studio di soluzioni nuove, in particolar modo per quanto riguarda l'integrazione di più sistemi satellitari. In numerosi lavori è stata studiata l'influenza che l'utilizzo congiunto dei sistemi satellitari GLONASS e GPS hanno in un rilievo topografico. Tuttavia, scopo di questo articolo scientifico non è tanto quello di valutare questa influenza, ma di dare un forte apporto allo sviluppo di un nuova metodologia, del tutto innovativa, denominata Multiconstellation. L'approccio Multiconstellation, come è noto in letteratura, è stato introdotto qualche anno or sono dai ricercatori dell'area Geomatica dell'Università La Sapienza di Roma; da allora sono stati compiuti alcuni lavori con tale approccio con sessioni limitata ad una durata di 30 minuti, su basi di lunghezza minima. Con questo nuovo metodo, modificando i files RINEX originali mediante l'utilizzo del software Multicon, è possibile raddoppiare il numero di basi linearmente indipendenti per sessione, dimezzando pertanto il numero di sessioni da utilizzare e quindi il tempo necessario per eseguire l'intero rilievo. Considerando che nella pratica professionale un topografo utilizza spesso strumenti noleggiati e software commerciali per le elaborazioni dei dati, dimezzare i tempi complessivi di un rilevo implica diminuire i costi complessivi dello stesso. Essendo quindi evidenti i vantaggi teorici di questo nuovo approccio rispetto a quello tradizionale, si è pensato di valutare la sua affidabilità in termini di precisioni raggiungibili con sessioni di durata più lunga di quelle utilizzate negli anni scorsi, cioè con durata temporale estesa tra le 3 e le 12 ore, considerando i dati provenienti dalla rete sperimentale gestita dal DICAM dell’Università di Palermo, mediante l’utilizzo dei principali software commerciali delle più prestigiose case produttrici mondiali (Leica LGO ver.8,0, Topcon Pinnacle ver 1.0, Topcon Tools ver. 8.0, Trimble Business Center)

Encapsulation Techniques and Traffic Characterisation of an Ethernet-Based 5G Fronthaul

This paper first overviews how, in the 5G Next Generation Radio Access Network (NG-RAN), the Next generation NodeB (gNB) functions are split into Distributed Unit (DU) and Central Unit (CU). Then it describes the proposed fronthaul transport solutions, such as Common Packet Radio Interface (CPRI), eCPRI, IEEE P1914.3 and their relationship with the Ethernet protocol. Finally, a characterisation of the traffic generated by the fronthaul is presented. Such characterisation may guide in the selection of the right network for fronthaul transport.This work has been partially funded by the EU H2020 “5G-Transformer” Project (grant no. 761536)